Excessive International Roaming Charges Without Using The Phone?

This is my nightmare story with my little smart phone, Fido and my trip to Europe. First of all, I want to tell you that I'm not an avid phone user and many times I forget my Samsung at home. We bought a family package at the end of 2011 to be in touch with our two boys and check them where they are and what they are doing. They are going through the delicate teen years... At the end of May I had to travel to Europe to see my old parents after 4 years of absence and unfortunately took with me accidentally my smart phone (if you can call it smart!). Luckily, I forgot my charger and the universal plug adapter to be able to use my North American phone abroad. While in the plane, as a good citizen I turned it off following the basic rules of the flight. While enjoying blue skies at 10.000 meters, I took two pictures of the red wing of the Austrian Airliner as a souvenir. In Vienna, I had to wait for more than 10 hours for my connecting flight and once in a while I used my phone to check the time while reading a book in the waiting room. I took also a picture of the airport but, I didn't call anybody in the world and I didn't send message to anybody in the world. Once arrived in Europe, the battery of my cell was almost dead (the battery can't last more than 24 hours). I put the phone at the bottom of my suitcase and left it there for the whole period of my stay in Europe. The shocking surprise when I came back in Toronto was the Fido bill: usually as a family we pay $56-57 monthly, the actual bill reads $157!!! I called immediately Fido and they told me I have to pay all this amount because is not responsibility of the company to explain to its costumers what to do when they travel abroad. I pointed out that facts are clear: I'm new with the use of the smart phone, I didn't call, I didn't send text messages while I was away, but I was charged big money for the international roaming. I insisted that I can't pay this money especially now that I remained unemployed but Fido didn't seem to listen to my complaint and said that I have to educate myself about everything! Can you advice please, what to do in this complicated case? Thank you in advance